The US now has its first nationally representative, blood-based benchmark for omega-3 status, which has revealed that most Americans are falling short.
Published in Current Developments in Nutrition by researchers from the CDC's National Center for Health Statistics, the study measured red blood cell fatty acids in 7213 participants aged six and older, using NHANES data collected between August 2021 and August 2023.
It is the first time NHANES has directly measured the Omega-3 Index (O3I) — EPA plus DHA as a percentage of red blood cell fatty acids — rather than relying on dietary recall.
Almost nobody hits optimal
The findings are stark. Fifty-four per cent of the population had an undesirable O3I (below four per cent) and 97.9% fell below the eight per cent optimal threshold.
So few individuals reached optimal levels that the researchers could not actually report a reliable prevalence for that category at all.
Mean O3I across the whole population was 4.12%, rising to 4.25% among adults, with children (3.61%) and adolescents (3.60%) faring worse.
Where the opportunity lies
For formulators, the subgroup data is also an interesting — and, crucially, actionable — story.
O3I rose with age and was significantly higher among women, non-Hispanic Asian adults, those with education beyond high school and adults above the poverty line, pointing to clear socioeconomic and demographic gaps in omega-3 status.
Most importantly, PUFA-containing dietary supplement use emerged as the strongest independent predictor of higher O3I in adjusted models, outperforming even dietary intake quartiles.
Smoking and obesity were independently associated with lower levels, aligning with roughly 40% of US adults living with obesity and 16 million with smoking-related disease.
The authors noted that only 24.3% of US adults reported eating seafood twice weekly or more during the survey period (which is well short of American Heart Association guidance), reinforcing supplementation as a practical route to closing the gap for most consumers.
The news also comes shortly after a landmark meta-analysis of 35 trials found no increased atrial fibrillation risk at nutritional EPA+DHA doses — addressing a safety concern that had shadowed the category.
With a government-generated, biomarker-verified baseline now established, manufacturers have a far stronger evidence base for consumer education, retailer engagement and regulatory or policy conversations than dietary-recall data has ever provided.
The authors themselves frame the dataset as groundwork for future public health strategy — suggesting this benchmark and the subgroup gaps it exposes will shape omega-3 positioning and targeting for some time to come.
